Receiving apparatus for eliminating static



Jan. 27, 1925. 1,524,645

- M. LATOUR RECEIVING APPARATUS YFOR ELIMINATING STATIC Filed Aug. 19, 1921 76 jndtmto/ Patented `lan. Z7, 1925..

er ras p l MABIUS LATOUR, or ramsranncn.

RECEIVING APPARATUS FOR ELIMINATING- STATIC.

Application filed August 19,/1921. ySerial lo. 493,679.

(GRANTED UNDER THE PROVISIONS F THE ACT 0F MARCH 3, 1921, 41 STAT. 11,1313.)

T 0 all whom it may concern:

Be it known that I, MARiUs LA'roUn, a citizen of the Republic of. France,and a resident of Paris, France, have invented a certain new and useful Improvements in Receiving Apparatus for Eliminating Static A (for which I- have filed an application in France `May 25, 1920, Patent No. 526,674), of which the following is-a specification accompanied by drawings. .l

rIhis invention relates to circuit arrangements applicable to wireless telegraph receivers. rIhe object of the'circuit arrangement is to reduce the disturbances caused by atmospheric disturbances caused by atmospheric discharges, and particularly in rcase continuous waves are used and the receiving is registered.

In accordance with the present invention two signals received are opposed to each other after detection, in the manner which is hereinafter set forth.

Lgf' the drawing Fig. 1, is a diagrammatic illustration o f a system for receiving waves which' are not'modulated in transmission at musical frequency.

Fig. 2 is a modication for receiving signals modulated at a musical frequency at the transmitter.

In accordance with theA arangement shown in Fig. 1, continuous waves are received without the use of the heterodyne. One signal is received'on the frame 1 tuned exactly to the wave length to be received, and the other signal is received on the frame 2 which is slightly detuned with respect to this wavelength. The arrangement comprisesI de.

tector tubes 3 and 4 having resistances 5 and 6 in the platecircuits. A 'registerable di- Yrect current potential is collected between points 7 and 8 of the resistances, and this current substantially represents the transl mission freed from all atmospherics, because in accordance with the hypothesis of energizing two frames by a shock, after detection, the atmospherics assume the same aspect in the two receiving circuits. This direct current potential could be amplified in accordance with the arrangementy described in af French Patent No. 512,629, granted October 18, 1920, entitled: `Proportional amplifying arrangement forl direct current potentials to be used for the transmissionlto 'a distance of `pictures and for telegraph relays.

modulated at the sending station to a musical frequency, a double detecting arrange.b

ment may beprovided in the mann'er shown in Fig. 2. y v

Illhe plate circuits of tubes 3 and 4 comprise in this case transformers 15, 17, and 16, 18, tuned to the tone of the modulation, or a multiple resonance amplifier having a ,musical frequency, instead of the resistances that were provided in the previously described example. The current of musical `frequency thus received at the station as well as the disturbing currents that may enter into such circuits, will be rectified or detected for a second time e. g. by means of tubes, 13 and 14. Only after this second detection will we observe an opposition of the two currents received in the resistances 5 and 6.

If the station itself does not send out musical tones, provision may be made for a second rectifying or detection, by using in the two receiving circuits two synchronous tickers, 19, 20. These tickers could be arranged .on the outgoing transformers 15 and 16. t

If heterodyne receiving is desired, preferl ablytwo distinct heterodynes 21, 22, should, Abe used that separately energize the frames Having .described my invention what I claim is:

1. In systems for reducing static interference in radio reception, the combination of two loop antennae, a plurality of detectors,

one for each antenna, having .a portion of their output circuits, comprising a source otn direct current, common to both, a resistance in the output circuit or each detector, and indicating apparatus and connections from thel indicating apparatus to ,a point on each ot said resistances.

2. in systems for 'reducing Static interference in radio reception, the combination ,ot two loop antennae, one of said antennae being tuned and the other detuned with respect to the signal frequency, a piuraiity of detectors, one :For each antenna, haring a portion ot their output circuits, comprising5,`

a source otdirect current, common to tooth, a

resistance in each of the output circuitsand uuency currents, haring a portion ot their output circuits, comprising a Source ot direct current, common to both, a resistance in. the output circuits ot' each ot said last mentioned detecting means, and an indicator connected across both of said resistances. Y

d. .Tin systems ifor reducing static interference in radio reception, the combination of two ieop aeria'is, one tuned and the other detuned with respect to the sign-ai frequency, detecting apparatus, ampiiiiers in the circuits between the detectors and the aeriais, indicating apparatus, second amplifying apparatus in the circuits beta/en the indicating apparatus and the detectors, having a portion ot' their output circuits, comprising a source of direct current, in common, and a resistance in the circuit of the indicating apparatus, part Aoitsaid resistance being in the output circuit ci' oneof the amplifiers connected thereto and part in' the output circuit of tile other ainpiier also connected to the indicating' apparatus.,

LLTUUB. 

